1. Field of the Invention
The invention relates to a method for actuating an AC/DC voltage converter, having a DC voltage output, between which at least one series circuit of at least two capacitors and at least one series circuit of n switching elements is arranged, where n≧4. A connecting point of the switching elements between n/2 switching elements is connected to a connection for an AC voltage input. In addition, a series circuit of at least two diodes is connected in an antiparallel arrangement at least to the series circuit of the two switching elements situated closest to said connecting point. Finally, a connecting point of the capacitors is connected to a connecting point of the diodes. In addition, a controller for implementing the method and an AC/DC voltage converter containing such a controller are specified.
AC/DC voltage converters are known in principle and are used whenever an AC voltage has to be converted into a DC voltage, for example when charging circuits for accumulators or for supplying the intermediate circuit of an inverter. An AC/DC voltage converter may therefore also be part of an AC/AC converter. AC/DC voltage converters are often also operated in both directions, in which case they can also operate as DC/AC voltage converters.
The disadvantage of the known AC/DC voltage converters and methods of controlling them is that the numerous demands placed on these devices, such as keeping the output voltage constant with a varying energy flow, controlling the total current of the phases connected to the AC voltage input, controlling any one phase between the input current and input voltage as well as maintaining a sinusoidal input current with as little ripple as possible, can be met to only an unsatisfactory degree.